Complete determinism is, as Karl Popper said, “a daydream of omniscience.” Determinism is usually conceived as linked with a particular science whose explanations are deemed fundamental. As Rose rightly points out, biological enquiry includes many different kinds of question. Genetic determinism, making genes central to biology, is therefore biased and misguided. The crucial unit must be the whole organism. Correspondence:c1 IA Collingwood Terrace, Newcastle on Tyne NE2 2JP, United Kingdom mbm@coll1a.demon.co.uk.